Various techniques are known for attaching the end of a strip of film or other web material to a spool. For example, a film end can be attached to a spool by a piece of adhesive tape. Also, it is known to provide a slot in a spool with one or more teeth or hooks in the slot for engaging openings in an end portion of the film to attach the end portion to the spool. It is also known to use a pin or other kinds of locking members for holding an end portion of film in a spool slot.
When the film has been attached to the spool, the spool is rotated to wind a predetermined length of the film onto the spool. Then the spool can be loaded into a cassette. Film can be removed from the spool by pulling the end of the film opposite from its attachment to the spool away from the spool, as in conventional 35 mm film cassettes. However, in some instances it is desirable to have all of the film wound into the cassette and then to drive the film out of the cassette by rotating the film spool within the cassette in an unwinding direction. In order to thrust the film out of the cassette in this manner, a force must be exerted on the film in its lengthwise direction. If the film is attached by conventional methods, such as adhesive tape or by inserting the film into a slot and engaging it with hooks in the slot, there may not be sufficient rigidity or beam strength in the film to effect thrusting of the free end of the film out of the cassette. The spool of the present invention overcomes this problem and provides a unique and improved manner for attaching the film to the spool.